Two new retractors for use in cryotherapy

Brirish Jo,mai of Oral and MasrNo/ucml Sur,qen (1997) 35, 199-200 G 1997 The Bntlsh Associatm of Oral and Maxillofaaal Surgeons

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TECHNICAL NOTE Two new retractors for use in cryotherapy R.T. Rees, J. E. Rowson Departments oj’Maxillojbciu1

Surgery, West Norwich Hospital, Norwich and General Hospital, Nottingham.

SUMMARY. Two new instruments are described for use in the cryotherapy of peripheral nerves. They are designed to give good vision and access, protect surrounding tissues and be comfortable to hold.

LC:,

INTRODUCTION

TECHNIQUE

Cryotherapy is an established treatment in the surgical management of trigeminal neuralgia. It is used to produce cryo-lesions of peripheral branches of the trigeminal nerve where they are most easily accessible. The branches most commonly treated are the infraorbital branch at the infra-orbital foramen, the inferior alveolar branch at the lingula, the mental branch at the mental foramen and, occasionally, the long buccal branch in the retro-molar region. Obtaining a clear view whilst, at the same time, protecting surrounding tissues is important, particularly in the cases of the infra-orbital and inferior alveolar nerves where access is more restricted. Although a variety of retractors may be used, none are ideal and often a combination of two retractors is necessary, making it more difficult to control the surrounding tissues especially for a single operator. Two simple retractor designs are described which allow clear vision and easy access and, at the same time, protect adjacent tissues and are comfortable for the assistant to hold (Fig. 1). The instruments will shortly be available from DePuy Healthcare.*

A. Infra-orbital

Fig. 1 - Inferior ,’i retractors

Alveolar

(top)

* Rees-Rowson Viaduct Road.

Cryotherapy Leeds LS4 2BR.

and Infraorbital

Retractors.

nerve

The infra-orbital nerve is approached in the usual manner via a mucosal incision in the buccal sulcus. The buccal tissues are elevated to expose the nerve. Mobility of the nerve trunk may be enhanced by elevating the periostium around it with an instrument such as a Warwick James elevator. The infra-orbital nerve retractor is then slid under the flap, so as to site the nerve trunk in the groove of the blade. The tip of the instrument may in addition be slipped over the infra-orbital margin for extra stability. The nerve is now well exposed and the buccal tissues are held neatly out of the way by the flange (Fig. 2). B. Inferior alveolar nerve

For the inferior alveolar nerve a standard incision in the third molar region is followed by careful elevation of the lingual periostium distally towards the lingula. As the lingula is approached the inferior alveolar retractor is slid into place and using an instrument such as a Howarth’s periosteal elevator the nerve is gently exposed and the retractor positioned so as to allow the nerve trunk to fall in the groove of the

(bottom)

DePuy

Healthcare, Fig. 2 - lnfraorbital 199

retractor

in use

200

British

Journal

of Oral

and Maxillofacial

Surgery

blade. The nerve is now well-exposed and the blade of the retractor holds both the lingual mucosa and tongue conveniently out of the way. Acknowledgements The authors would like to thank the Department of Maxillofacial Technology, West Norwich Hospital who helped construct the prototypes and the Instrument Workshop at the Norfolk and Norwich Hospital who made up the final designs.

The Authors Roger T. Rees MB, BS, FDSRCS Consultant

Department of Maxillofacial Surgery West Norwich Hospital Bowthorpe Road Norwich NR2 3TU John E. Rowson BMedSci, FRCS, FDSRCS Senior Registrar Department of Maxillofacial Surgery General Hospital 30 The Ropewalk Nottingham NGI SDW Correspondence and requests for offprints to Roger T. Rees Paper received 22 February 1995 Accepted 19 June 1995